Abstract: A multi-wavelength light source includes a laser, an optical modulator, an optical mixer, an optical demultiplexer, and an optical power adjuster that are sequentially coupled. The laser is configured to generate a first optical signal. The optical modulator modulates the first optical signal, to generate a second optical signal, where the second optical signal includes at least two wavelength components. The optical mixer mixes frequencies based on the at least two wavelength components to generate a third optical signal, where the third optical signal includes at least four wavelength components. The demultiplexer separates the at least four wavelength components. The optical power adjuster adjusts, based on a specified power threshold, a power of each of the wavelength components obtained by separation by the demultiplexer.

Abstract: The present invention discloses a receiving apparatus, a sending apparatus, a system and a method for optical polarization division multiplexing.

Abstract: In the field of communications transmission, a method, a device, and a system for generating and receiving a phase polarization modulated signal are disclosed. The device for generating the phase polarization modulated signal includes: a Laser Diode (LD), a time division demultiplexer, a phase precoding module, a phase modulating module, a polarization precoding module and a polarization modulating module. The device for receiving the phase polarization modulated signal includes: an optical splitter, a polarizer, a phase demodulating and receiving unit, a Polarization Beam Splitter (PBS), a balanced receiver, a power divider, an exclusive OR, a delayer and a data interface processing unit. Therefore, problems in the prior art that a Differential Quadrature Phase Shift Keying (DQPSK) signal cannot bear and transmit information at a higher rate and that non-linear effect is strong during transmission are solved, and transmission performance of an optical signal is improved.

Abstract: A Passive Optical Network (PON) multicast management method includes: an Optical Line Terminal (OLT) performs multicast control according to multicast control information, and generates a corresponding multicast downstream command; the OLT sends the multicast downstream command to an Optical Network Unit (ONU); and the ONU resolves the multicast downstream command, and performs multicast control according to the multicast downstream command. Accordingly, a PON multicast communication system, an OLT, and an ONU are disclosed. Through the multicast control mechanism introduced into the PON system, the PON multicast functions are enhanced, and the same data destined for multiple ONUs is prevented from being sent repeatedly in the network, and thus the network bandwidth resources are saved.

Abstract: The embodiments of the present invention disclose a system, a method, and a device for polarization multiplexing. The method includes: co-direction judgment: after judging that the similarity between the control quantities of the two optical signals meets a predetermined similarity criterion, enabling at least one of the two branches to re-search for the control quantity until the similarity between the control quantities of the two optical signals does not meet the predetermined similarity criterion. The preceding technical solution may substantially prevent the optical signals output by the two branches at a receiving end from having the co-directional state of polarization, without affecting the complexity and implementation cost of the system and the processing time delay of data signals at the receiving end.

Abstract: The present invention discloses a receiving apparatus, a sending apparatus, a system and a method for optical polarization division multiplexing.

Abstract: A method and an apparatus for generating a differential quadrature phase shift keying (DQPSK) code optical signal are provided. The method may includes splitting an optical signal to obtain two polarized optical signals, modulating and phase-shifting one of the two polarized optical signals to obtain a phase-shifted and polarized optical signal, and modulating the other of the two polarized optical signals to obtain another polarized and modulated optical signal. The phase-shifted and polarized optical signal may be combined with the other polarized and modulated optical signal to obtain a polarization multiplexed optical signal. The method may further include, polarizing the polarization multiplexed optical signal to obtain the DQPSK code optical signal. The apparatus may include a polarization beam splitter (PBS), modulators, a phase-shift controller, a polarization beam combiner (PBC), and a polarizer.

Abstract: In the field of communications transmission, a method, a device, and a system for generating and receiving a phase polarization modulated signal are disclosed. The device for generating the phase polarization modulated signal includes: a Laser Diode (LD), a time division demultiplexer, a phase precoding module, a phase modulating module, a polarization precoding module and a polarization modulating module. The device for receiving the phase polarization modulated signal includes: an optical splitter, a polarizer, a phase demodulating and receiving unit, a Polarization Beam Splitter (PBS), a balanced receiver, a power divider, an exclusive OR, a delayer and a data interface processing unit. Therefore, problems in the prior art that a Differential Quadrature Phase Shift Keying (DQPSK) signal cannot bear and transmit information at a higher rate and that non-linear effect is strong during transmission are solved, and transmission performance of an optical signal is improved.

Abstract: A ranging method and system for passive optical network, and an optical network unit are provided. The ranging method includes: sending an initial ranging signal to a splitter loop-back device and recording a current sending time as a first time; receiving a loop-back ranging signal from the splitter loop-back device, and determining whether the loop-back ranging signal is a return signal of the initial ranging signal; if the loop-back ranging signal is a return signal of the initial ranging signal, recording a current receiving time as a second time; and obtaining ranging information by calculating a difference between the first time and the second time, and performing a ranging on the basis of the ranging information.

Abstract: An optical transmission system, an optical transmitting apparatus, an optical transmitting method, an optical receiving apparatus, and an optical receiving method are provided. The optical transmitting apparatus includes a pre-coding module, a multiplexing module, and a modulating module. The optical receiving apparatus includes a demodulating module and a converting module. The optical transmitting method includes: performing pre-coding, multiplexing, and modulation for a signal to be transmitted, and then outputting the signal.

Abstract: A method and an apparatus for generating a differential quadrature phase shift keying (DQPSK) code optical signal are provided. The method may includes splitting an optical signal to obtain two polarized optical signals, modulating and phase-shifting one of the two polarized optical signals to obtain a phase-shifted and polarized optical signal, and modulating the other of the two polarized optical signals to obtain another polarized and modulated optical signal. The phase-shifted and polarized optical signal may be combined with the other polarized and modulated optical signal to obtain a polarization multiplexed optical signal. The method may further include, polarizing the polarization multiplexed optical signal to obtain the DQPSK code optical signal. The apparatus may include a polarization beam splitter (PBS), modulators, a phase-shift controller, a polarization beam combiner (PBC), and a polarizer.

Abstract: A Passive Optical Network (PON) multicast management method includes: an Optical Line Terminal (OLT) performs multicast control according to multicast control information, and generates a corresponding multicast downstream command; the OLT sends the multicast downstream command to an Optical Network Unit (ONU); and the ONU resolves the multicast downstream command, and performs multicast control according to the multicast downstream command. Accordingly, a PON multicast communication system, an OLT, and an ONU are disclosed. Through the multicast control mechanism introduced into the PON system, the PON multicast functions are enhanced, and the same data destined for multiple ONUs is prevented from being sent repeatedly in the network, and thus the network bandwidth resources are saved.

Abstract: A ranging method and system for passive optical network, and an optical network unit are provided. The ranging method includes: sending an initial ranging signal to a splitter loop-back device and recording a current sending time as a first time; receiving a loop-back ranging signal from the splitter loop-back device, and determining whether the loop-back ranging signal is a return signal of the initial ranging signal; if the loop-back ranging signal is a return signal of the initial ranging signal, recording a current receiving time as a second time; and obtaining ranging information by calculating a difference between the first time and the second time, and performing a ranging on the basis of the ranging information.